The building industry is a multi-billion dollar industry. Ways are always being sought to make construction more efficient and less costly.
Over time there has been an evolution in the types of materials used in construction, from wood and clay, to brick, steel and cement. Today, plastic has become a material much used in building. There is an emphasis on efficiency and cost effectiveness. Many of the building materials are modular and prefabricated. Over the years improvements have been made in the construction and the installation of window and door frames. The instant invention is concerned with improvements in the construction and installation of door frames. The invention will find applicability in all sorts of construction, from simple housing, to major construction such as apartments, hotels, hospitals and office buildings.
In the prior art the leveling of doors and window frames to make them plumb or level was done by the use of shims or wedges. For example, the door frame was leveled and a shim was forcibly inserted between the bottom of the door jamb and the floor. It is not difficult to imagine that this method was inefficient because to place the shim or shims accurately was time consuming. Further, once the shim was in place it was easy to knock or kick out of place from under the door jamb. In fact the shim was often knocked out of place by construction workers passing the door jamb area. Moreover, the shims were also prone to be knocked out by carpet layers, floor finishers or by the cleaning crew working around the door. Once the shim was knocked out, the door frame became unlevel, and no door could be properly hung. To relevel the door frame a carpenter had to be taken off his job, level the door frame and reset the shim. It is not hard to recognize that the replacement of the accidentally removed shim was time consuming, expensive, and particularly burdensome in construction where costs had to be kept low and the budget maintained.
The invention herein disclosed seeks to eliminate the problem of the accidentally removed shim.
The patent literature sets forth examples of door frame leveling in building construction.
U.S. Pat. No. 1,179,597, issued to Zahner, is directed to a door frame fastener attached to sheet metal door and window frames. The fastener is affixed so that no screws or bolts are visible after the frame has been assembled. The method taught by Zahner allows for vertical and horizontal adjustments of the cases and then the permanent securing of the case. All this is accomplished by the use of a bolt and split nut. The head of the bolt rides in a slot on the inside of the door frame with the split nut being attached in a slot in the door buck. Once the frame is in its proper position the frame outside and opposite the head of the bolt is tapped and the bolt within the split nut binds and secures the frame. A major disadvantage to the frame installation described in the Zahner patent is the fact that once the frame is installed there is no opportunity for further adjustment if the frame becomes unleveled at a future time.
Nelson, in U.S. Pat. No. 1,754,762, sets forth a rather complicated method of securing doors and windows to frame members. Nelson uses adjustable spacing members through which extend screws to secure frame members. The frame member is secured through a bracket attached to a plug in the ground or floor of the building structure. The bracket has a threaded portion through which a screw attached to the frame is inserted, and the frame is adjusted by screwing the screw into the threaded bracket. Nelson's system is cumbersome.
Another rather complicated method for adjusting a door jamb is taught by Tolman in U.S. Pat. No. 2,742,117. The Tolman method involves two mated halves of a door jamb or window. One half of the jamb or window is on one side of the wall and the other half is on the other. Screws are used to securely attach the two halves and added tension is placed on the screws to tighten the two halves to the building structure.
Allen, in U.S. Pat. No. 4,478,016, discloses a door jamb leveler of rather complicated construction and involved operation. The Allen device employs a flange and bar under a jamb. A screw is turned to raise and level the door jamb. Once the jamb is level the frame is permanently secured to the building and the leveling device is removed. No leveling device fixed to the jamb is disclosed by Allen.
None of the prior art teaches a door jamb leveling device which allows for the easy, uncomplicated leveling of the door frame followed by the quick secure fixing of the jamb to position the door frame in a level orientation.